The overall objective of this project is to conduct a series of coordinated studies designed to characterize and quantitate the thermoregulatory responses of an infrahuman primate, the rhesus monkey, over a wide range of ambient conditions before and after heat and cold acclimatization. These studies will provide a data base upon which to$ evaluate this higher primate as a viable model for temperature regulation studies which cannot be directly performed on man. Such a model would also be used to quantitate and differentiate the basic changes in thermoregulatory function occurring centrally in the CNS control centers and peripherally at the level of the effectors, i.e., sweat glands and vasomotor system associated not only with the natural adaptive processes of cold and heat acclimation, but will also be used to study thermoregulatory malfunctions associated with disease states such as fever and heat stroke. BIBLIOGRAPHIC REFERENCES: Elizondo, R.S., K. Smiles, and C. Barney. Effects of local hypothalamic heating and cooling on the sweat rate in the rhesus monkey. Israel Journal of Medical Sciences 12: 1026-1028, 1976. R.S. Elizondo. "Temperature Regulation in Primates", Chapter III Environmental Physiology II, International Review of Science, 1977, in press.